Ukrainian authorities ordered a mandatory evacuation Thursday of nearly 12,000 civilians from 37 towns and villages in the eastern Kharkiv region, where Russian forces reportedly are making a concerted effort to punch through the front line.

The local military administration in Kharkiv’s Kupiansk district said residents must comply with the evacuation order or sign a document saying they would stay at their own risk.

Hanna Maliar, Ukraine’s deputy defence minister, had said the previous day that “the intensity of combat and enemy shelling is high” in the area.

Russia Ukraine War
The city of Kupiansk and the territories around it were under Russian occupation until September 2022 (Evgeniy Maloletka/AP)

The city of Kupiansk and the territories around it were under Russian occupation until September 2022, when Ukrainian forces conducted a rapid offensive operation that dislodged the Kremlin’s forces from nearly the entire Kharkiv region.

The re-taking of those areas strengthened Ukraine’s arguments that its troops could deliver more stinging defeats to Russia with additional armament deliveries, which its Western allies duly provided.

But as Ukraine has pursued a slow-moving counteroffensive in recent weeks, Russian forces have struck back in some areas.

Ms Maliar said Russia “has formed an offensive group and is attempting to move forward” in the area in an effort to advance on the Ukrainian-held city of Kupiansk, which is an important rail junction.

It was not possible to independently verify either side’s claims.

Ukrainian soldiers on the front line in Donetsk
Ukrainian soldiers on the front line in Donetsk (Libkos/AP)

Earlier Thursday, Russian air defence systems shot down two drones heading toward Moscow for a second straight day, officials said.

The attack disrupted flights at two international airports as Ukraine appeared to step up its assault on Russian soil.

One drone was downed in the Kaluga region south-west of Moscow and another near a major Moscow ring road, according to Moscow mayor Sergey Sobyanin and the Russian Defence Ministry, which blamed the attack on Ukraine.

No casualties or damage were immediately reported.

Domodedovo airport, south of the city, halted flights for more than two hours and Vnukovo airport, south-west of the city, stopped flights for more than two-and-a-half hours and redirected some incoming aircraft to other airports, according to Russian news agencies.

A Ukrainian serviceman fires a cannon towards Russian positions at the front line in Donetsk
Ukraine has been promised more weapons and ammunition to help sustain its counter-offensive (Libkos/AP)

It was not clear where the drones were launched, and Ukrainian officials made no immediate comment. Ukraine usually neither confirms nor denies such attacks.

Firing drones at Moscow after more than 17 months of war has little apparent military value for Ukraine, but the strategy has served to unsettle Russians and bring home to them the conflict’s consequences.

Air Force spokesman Yurii Ihnat said: “This cannot but please us because people in Moscow thought they were safe. Now, the war affects each and every Russian.”

“We now see that ‘something’ happens in Moscow on a regular basis,” he added.

Russia’s Defence Ministry also said it had stopped Ukrainian drone attacks in Moscow-annexed Crimea. It said it shot down two drones near the port city of Sevastopol and electronically jammed nine that crashed into the Black Sea.

A woman reacts at the scene of a building damaged after recent Russian missile strikes
As Ukraine has pursued a slow-moving counteroffensive in recent weeks, Russian forces have struck back (Libkos/AP)

On Wednesday, Ukrainian media reported social media blogs as saying that a thick plume of smoke billowed over Sevastopol, which is the headquarters of Russia’s Black Sea Fleet.

The governor of Sevastopol, Mikhail Razvozhayev, said the smoke came from a “fleet training exercise” and urged local residents not to worry.

The incidents have come against the backdrop of Ukraine’s ongoing counter-offensive, which Ukrainian and Western officials have warned will be a long slog against the Kremlin’s deeply entrenched forces.

The Pentagon is to provide Ukraine with another 200 million dollars (£156.75 million) in weapons and ammunition to help sustain the counter-offensive, according to US officials.

Ukraine has already received more than 43 billion dollars (£33.7 billion) from the US since Russia invaded last year.

Ukraine’s presidential office said at least six civilians were killed and 27 were injured between Wednesday and Thursday mornings.

The site of the Zagorsk Optical and Mechanical Plant after an explosion
The Zagorsk Optical and Mechanical Plant was destroyed (Russian Emergency Ministry Press Service via AP)

In eastern Ukraine’s Donetsk province, Russia shelled 16 cities and villages, and three people were killed, the office reported. In Zaporizhzhia, three people were killed and nine wounded, including an 11-month-old baby.

Meanwhile, 12 people remained missing after an explosion on Wednesday at a factory that makes optical equipment for Russian security forces, Russia’s state news agency RIA Novosti reported, citing emergency officials.

Russia’s Emergency Ministry said 71 people required medical assistance after the explosion.

Russian officials did not offer a suspected cause of the explosion at the Zagorsk plant in the region around Moscow, which added to jitters about potential Ukrainian drone strikes.

The fallout from Russia’s war against Ukraine has brought concerns to neighbouring countries, including the presence of Russia-linked Wagner group mercenaries in Belarus this summer after their short-lived mutiny in Russia.

Poland’s defence minister said the country intends to put 10,000 soldiers along its border with Belarus amid fears of a spike in illegal immigration.

Polish officials have accused Belarusian authorities of organising illegal border crossings to disrupt and pressure Warsaw, which along with other Nato countries has provided support for Kyiv’s war effort.